This invention proposes a novel common packet data channel (CPDC) system structure and method to efficiently provide variable-rate packet data services in CDMA system. This system uses common code channels to serve packet data calls for a plurality of packet data users within a cell or sector. On the forward link (base station-to-mobile), an ATM-type multiplexing scheme is employed on a common code channel, while a spread ALOHA-type random access scheme is used on the reverse link (mobile-to-base station). The overhead due to call setup and channel assignment in a conventional circuit-switched system is not required in this system. The delay due to the call setup is reduced. In addition, ATM cells can be directly transmitted over the air interface. Novel transceiver architectures for the terminal and base station for implementing a system as well as particular channel signal structures are disclosed.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of providing both packet-based services and stream-based services in a CDMA network having at least one base station and a plurality of terminals, said method comprising: a) allocating distinct spreading code sequences for each stream-based service; b) allocating shared spreading code sequences for a plurality of packet-based services such that more than one terminal can use the shared spreading sequences; c) allocating a packet data control broadcast sequence for forward link control communications between said base station and said plurality of terminals; d) for packets to be transmitted on the forward link, transmitting packets using a shared spreading sequence on a sequential basis; and e) for packets to be transmitted on the reverse link, each terminal transmits packets using a shared spreading sequence whenever said terminal has packets ready for transmission, provided said network is not congested.
2. A method of providing both packet-based services and stream-based services in a CDMA network having at least one base station and a plurality of terminals, said method comprising: a) allocating a distinct channel for each stream-based service; b) allocating at least one shared forward link channel and at least one shared reverse link channel for a plurality of packet-based services such that more than one terminal can use the shared channels; c) allocating a packet data control broadcast channel for forward link control communications between said base station and said plurality of terminals; d) on the reverse link, whenever a terminal has packets ready for transmission, before transmitting said packets said terminal: I) determines whether the system is congested; and II) if not congested, transmitting a request to said base station.
3. The method as claimed in claim 2 wherein step (d) further comprises: III) responsive to a determination the network is congested, waiting a random time and then proceeding with step I) again.
4. The method as claimed in claim 3 wherein step (d) further comprises: IV) monitoring communications from said base station for an acknowledgement of said request; and V) upon receiving acknowledgement of said request, transmitting said packets.
5. The method as claimed in claim 4 wherein step (d) further comprises: VI) while no acknowledgement of said request has been received, continuing to transmit said request until a specified period of time expires.
6. The method as claimed in claim 3 wherein step (d) further comprises: IV) after transmitting said request, transmitting packets; V) monitoring communications from said base station for an acknowledgement of said request while transmitting said packets; and VI) if no acknowledgement of said request is received within a specified time, waiting a random time and then commencing with step I again.
7. The method as claimed in claim 4 wherein packets transmitted on said at least one shared channels comprise header, payload and error detection parts, wherein said header and payload cooperate to include power control information.
8. The method as claimed in claim 4 wherein packets transmitted on said at least one shared channels comprise header, payload and error detection parts, wherein said payload includes power control information.
9. The method as claimed in claim 2 wherein packets transmitted on said at least one shared channels comprise header, payload and error detection parts, said method further comprising the steps of: producing frame structure to be transmitted, said frame structure including packets to be transmitted and subchannel information; and transmitting said frame structure.
10. The method as claimed in claim 4 wherein packets transmitted on said at least one shared channels comprise header, payload and error detection parts, said method further comprising the steps of: producing frame structure to be transmitted, said frame structure including packets to be transmitted and subchannel information; and transmitting said frame structure.
11. The method as claimed in claim 6 wherein packets transmitted on said at least one shared channels comprise header, payload and error detection parts, said method further comprising the steps of: producing frame structure to be transmitted, said frame structure including packets to be transmitted and subchannel information; and transmitting said frame structure.
12. The method as claimed in claim 9 wherein said subchannel information includes at least one flag and associated bits of subchannel information associated with said at least one flag, wherein the nature of said associated bits is determined by said at least one flag.
13. The method as claimed in claim 10 wherein said subchannel information includes at least one flag and associated bits of subchannel information associated with said at least one flag, wherein the nature of said associated bits is determined by said at least one flag.
14. The method as claimed in claim 11 wherein said subchannel information includes at least one flag and associated bits of subchannel information associated with said at least one flag, wherein the nature of said associated bits is determined by said at least one flag.
15. The method as claimed in claim 12 wherein said producing frame structure step comprises the step of puncturing said subchannel information into said frame structure.
16. The method as claimed in claim 12 wherein said producing frame structure step comprises the step of multiplexing said subchannel information into said frame structure.
17. The method as claimed in claim 12 wherein said at least one flag indicates whether said bits of subchannel information includes power control bits.
18. The method as claimed in claim 12 wherein said at least one flag comprises one flag per frame to each terminal using said shared channel pair and wherein each flag has an associated series of subchannel information bits located at regular intervals within said frame structure.
19. The method as claimed in claim 18 wherein said subchannel information comprises power control information and said one flag per frame per terminal indicates each associated series of subchannel bits directed to a terminal which is to receive power control information represents power control bits for adjusting the transmit power of said terminal.
20. The method as claimed in claim 2 wherein said request comprises a preamble which provides synchronization information to said base station.
21. The method as claimed in claim 18 wherein said request comprises a preamble which provides synchronization information to said base station.
22. The method as claimed in claim 20 wherein said preamble further comprises control information which identifies the requesting terminal to said base station.
23. A terminal for communicating with a telecommunications network using stream-based and packet based services comprising: a transceiver; a controller; memory for storing data and instructions for said controller; said controller adapted to store one set of spreading code sequences for accessing stream-based service channels and another set of spreading code sequences for accessing packet-based service channels.
24. A terminal as claimed in claim 23 wherein said instructions for said controller comprises: instructions for said controller to utilize spreading code sequences designated by a serving base station for packet communication with said base station; instructions for sending a preamble when the terminal desires to transmit packets for said packet based services; instructions to monitor communications from said base station using said spreading code sequences for an acknowledgement of said preamble from said base station; instructions for deciphering said acknowledgement; and instructions to said controller for transmitting packets once said acknowledgement is received.
25. A terminal as claimed in claim 23 further comprising: means for transmitting a preamble prior to transmitting packets when packets are to be transmitted using said packet-based service; and means for monitoring communications from a serving base station for a message acknowledging receipt of said preamble.
26. A terminal as claimed in claim 25 further comprising means for monitoring a channel for a congestion message from said base station, wherein said terminal only transmits said preamble if no congestion message has been received.
27. A terminal as claimed in claim 26 further comprising means for registration with said base station; and means for storing spreading code sequences received by said base station for packet bases services upon registration.
28. A terminal as claimed in claim 24 further comprising: a header processor for producing a header for outgoing packets and for setting a power control flag in said header to indicate said payload contains multiplexed power control bits; and means for multiplexing power control bits within said payload.
29. A terminal as claimed in claim 27 further comprising: a header processor for producing a header for outgoing packets and for setting a power control flag in said header to indicate said payload contains multiplexed power control bits; and means for multiplexing power control bits within said payload.
30. A terminal as claimed in claim 29 further comprising: a header detector for detecting a header in an incoming packet and determining whether a power control flag in said header indicates said payload contains multiplexed power control bits; and means for demultiplexing power control bits within said payload for use in adjusting the transmit power of said terminal.
31. A terminal as claimed in claim 24 further comprising: means for receiving a frame structure from a serving base station, wherein said frame structure includes information directed to a plurality of terminals; and means for extracting and processing information directed to said terminal.
32. A terminal as claimed in claim 27 further comprising: means for receiving a frame structure from a serving base station, wherein said frame structure includes information directed to a plurality of terminals; and means for extracting and processing information directed to said terminal.
33. A terminal as claimed in claim 31 wherein said frame structure includes packets and subchannel information directed to a plurality of terminals and wherein said means for extracting comprises: means for despreading and demodulating the frame structure; means for processing subchannel information directed to said terminal from said frame structure; and means for processing packets directed to said terminal from said frame structure.
34. A terminal as claimed in claim 33 wherein said means for processing subchannel information and said means for processing packets each receive at least a portion of said frame in parallel, such that said means for processing subchannel information can process said subchannel information without requiring said packets to be processed.
35. A terminal as claimed in claim 32 wherein said frame structure includes packets and subchannel information directed to a plurality of terminals and wherein said means for extracting comprises: means for despreading and demodulating the frame structure; means for processing subchannel information directed to said terminal from said frame structure; and means for processing packets directed to said terminal from said frame structure; wherein said means for processing subchannel information and said means for processing packets each receive at least a portion of said frame in parallel, such that said means for processing subchannel information can process said subchannel information without requiring said packets to be processed.
36. A terminal as claimed in claim 33 further comprising means for adjusting the transmission characteristics of said terminal responsive to said means for processing subchannel information.
37. A terminal as claimed in claim 36 wherein said subchannel information comprises power control information directed to said terminal and wherein said means for adjusting comprises means for adjusting the transmit power of said transceiver.
38. A terminal as claimed in claim 31 further comprising means for combining packets to be transmitted and subchannel information to be transmitted into a frame structure to be transmitted by said transceiver.
39. A terminal as claimed in claim 32 further comprising means for combining packets to be transmitted and subchannel information to be transmitted into a frame structure to be transmitted by said transceiver.
40. A terminal as claimed in claim 38 further comprising means for combining a pilot channel structure with said frame structure.
41. A terminal as claimed in claim 25 comprising: means for transmitting said preamble until a timer expires or said acknowledgement message is received; and means for transmitting said packets when said acknowledgement message is received.
42. A base station for providing stream based services and packet based services to terminals comprising: transmit means for transmitting forward link frame structures containing packet data to a plurality of terminals using a shared spreading code sequence; and receive means for receiving reverse link frame structures containing packet data from a plurality of terminals using a shared spreading code sequence.
43. A base station as claimed in claim 42 wherein said receive means comprises a plurality of receivers for processing a received frame structure; and further comprising means for allocating a received frame structure to an idle receiver.
44. A base station as claimed in claim 43 wherein said transmit means comprises means for producing a forward link frame structure to be transmitted comprises: means for combining packets and subchannel information directed to a plurality of terminals into a single frame structure.
45. A base station as claimed in claim 44 wherein each received frame structure comprises packets and subchannel information and wherein each receiver comprises means for processing subchannel information and means for processing packets.
46. A base station as claimed in claim 45 wherein said means for processing subchannel information and said means for processing packets each receive at least a portion of said received frame structure in parallel, such that said means for processing subchannel information can process said subchannel information without requiring said packets to be processed.
47. A base station as claimed in claim 46 further comprising a power control processor which determines the transmission characteristics of said forward link responsive to the means for processing subchannel information of the plurality of receivers; and means for adjusting the transmission characteristics of said forward link responsive to said power control processor.
48. A base station as claimed in claim 47 further comprising: means for monitoring communications from terminals registered to the base station for a preamble; and means for transmitting a message acknowledging receipt of said preamble.
49. A base station as claimed in claim 48 further comprising: means for transmitting a congestion message to terminals when there is congestion.
50. A base station as claimed in claim 49 further comprising: a header processor for producing a header for outgoing packets and for setting a power control flag in said header to indicate said payload contains multiplexed power control bits; and means for multiplexing power control bits within said payload.
51. A bas e station as claimed in claim 50 further comprising: a header detector for detecting a header in an incoming packet and determining whether a power control flag in said header indicates said payload contains multiplexed power control bits; and means for demultiplexing power control bits within said payload for use in adjusting the transmit power of said forward link.
52. A base station for providing stream based services and packet based services to terminals comprising: transmit means for transmitting forward link frame structures containing packet data to a plurality of terminals using a shared spreading code sequence; receive means for receiving reverse link frame structures containing packet data from a plurality of terminals using a shared spreading code sequence; and a controller for carrying out the method of claim 1 .
53. A base station for providing stream based services and packet based services to terminals comprising: transmit means for transmitting forward link frame structures containing packet data to a plurality of terminals using a shared spreading code sequence; receive means for receiving reverse link frame structures containing packet data from a plurality of terminals using a shared spreading code sequence; and a controller for carrying out the method of claim 2 .
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 4, 1998
May 14, 2002
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